<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
  </head>
  <body>
    <script>
      // 用户输入一个数字
      const x = prompt("第1个数字", 1);
      const y = prompt("第2个数字", 2);

      console.log(+x + +y); //12
    </script>
  </body>
</html>
